4 years later, and option 1 just saved me some grief.
I had 2 sessions open and autoindent started misbehaving, so I closed the window in which I had about 40 files open, and realized it, just too late. Re-opening one of the files, of course, opened it in the other session, where I had 1 file open. Luckily, the session.xml file had the large session, so all is good.
It’s not that my files were unsaved, it’s just that the session was set up in a convenient way for the work that I was doing.
Cheers for a helpful solution!